Natural oils provide chemical species that differ in structure from those generally obtained from traditional petroleum refining processes. In many instances, natural oils contain multifunctional moieties that contain, among other features, an ester or acid group and an olefinic group. When these natural oils are refined, the products obtained from the refining process can yield unique compositions that can serve as useful building blocks for various chemical uses.
Polyurethanes are a class of polymers having chains of organic units joined by carbamate linkages, but which can include other linkages as well. Polyurethanes can have a wide variety of physical properties, which depend, among other factors, on the combination and arrangement of monomers used to make the polyurethane and on the degree of cross-linking. Further, in some instances, polyurethanes can contain multiple blocks, where certain blocks are hard or rigid while others are soft and flexible. Alteration of the chemical structure, size and/or frequency of these segments in a polyurethane can allow for modification of the properties of the resin. These options can lead to resins having a wide array of different properties. Some of these resins can be thermosetting, while others can be thermoplastic.
Polyurethane foams can be used for a number of different applications. Polyurethane foams may be flexible or rigid, and can be used in a variety of different applications, including, but not limited to, use for foam insulation, use in packaging materials, and use in cushioning. Polyurethanes can also be used as elastomers. Polyurethane elastomers can be solid or porous, with representative applications including, but not limited to, textile fibers, coatings, sealants, adhesives, and resilient pads. Polyurethanes can also be used as thermosetting polymers. Representative applications of polyurethane thermosets include, but are not limited to, abrasion resistant wheels, mechanical parts, and structural materials.
It is desirable to expand the chemical structures present in polyurethanes, so as to expand the useful properties that can be provided by the polymers. For example, properties such as flexibility, toughness, etc. can be improved by incorporating chemical groups that lower the modulus or that can absorb energy, respectively. This expansion of chemical structures may be accomplished through post-polymerization processing, such as reaction with other reagents or blending with other polymers. It is especially desirable, however, to expand the chemical structures by introducing new chemical structures in the monomeric building blocks from which the polymer is formed.
Thus, there is a continuing need to develop new materials that can be incorporated into polymeric materials, such as polyurethanes, so as to develop resins having new and useful properties. Preferably such modified polyurethanes can be formed using conventional synthetic techniques and equipment, without requiring post-polymerization treatment. Preferably the modified polyurethanes can be formed using building blocks that are readily available and inexpensive.